Scandinavian Journal of Immunology

Production of novel peptide‐targeting antibodies for anti‐Müllerian hormone receptor 2 and induction of cytotoxicity in ovarian cancer cells

AbstractOvarian cancer is generally diagnosed at late stages. Monoclonal antibodies (MAbs) targeting antigens in ovarian cancer are used in the clinic. Anti‐Müllerian hormone receptor type 2 (AMHR2) is a receptor highly expressed in ovarian cancer and it is a potential target antigen for immunotherapy. Extracellular domain of AMHR2 was analysed in terms of 3D structure and physicochemical properties, and 3 peptide sequences (Peptides 1, 7 and 11) were determined as targets. MAb production protocol was performed, and 6 MAb clones showing high affinity for peptides were obtained. P3B1, P10A10, P10B6 and P2A6 clones were for peptide 11 (P11), P2C9 was for P7, and P6C5 was for P1. Antibody isotype of P2A6 was IgG2a and the others were of IgG1 isotype. MAb binding to the native recombinant protein (AMHR2‐Fc) was analysed by enzyme‐linked immunosorbent assay (ELISA) and MAb binding to AMHR2 expressed by SKOV‐3 ovarian cancer cells was analysed by western blot and immunofluorescent staining. P3B1 showed strong, P10A10, P10B6 and P2C9 showed medium affinity for the native protein (AMHR2‐Fc). P3B1 and P2C9 showed strong binding in western blot analysis. Clones showed moderate binding in immunoflorescent staining. A complement dependent cytotoxicity (CDC) experiment was conducted using MAbs and transfected SKOV‐3 cells. P3B1 induced a significant CDC. Variable regions of P3B1 MAb were sequenced. In conclusion, MAbs for three different regions of AMHR2 were produced. One clone was shown to induce cytotoxicity in ovarian cancer cells and its sequence was determined for future use as a humanised therapeutic MAb.

Is there a role played by HLA‐E, if any, in HPV immune evasion?

AbstractCervical cancer incidence worldwide exceeds half a million new cases per year. The human papillomavirus (HPV) being the major causative agent of CC uses a variety of strategies to evade immune surveillance, where the immune status varies amongst individuals. This immune evasion altered by HPV is reflected in persistent infections, causing the evolution of cervical neoplasia. The role of the immune system in viral recognition and elimination is of extreme relevance in the development of CC. The interactions of the HLA‐E ligand in the target cell along with CD94/NKG2 receptors, which are expressed predominantly, but not exclusively, on NK cells’ surface, are responsible for activating or inhibiting cytotoxic activity according to their function. The engagement between HLA‐E and CD94/NKG2 molecules is one of the fundamental surveillance mechanisms in patients with CIN I, II and III, where HLA‐E expression increases significantly, especially in HPV 16 and 18 infections. Higher HLA‐E expression was observed in most histopathological types of CC, and at the same time was correlated to best survival of the patient. This review aims to summarize and discuss the immunological role of HLA‐E in the context of HPV infection and immune system evasion, and the oncogenic process of cervical cancer.

Identification of tumour antigens and immune subtypes in the development of an anti‐cancer vaccine for endometrial carcinoma

AbstractTherapeutic application of vaccines to endometrial carcinoma (EC) remains uncertain. In this study, we aimed to identify potential tumour antigens for use in the development of an anti‐tumour mRNA vaccine and clarify immune subtypes and their characteristics for immunotherapeutic application in heterogeneous EC by integrating multi‐omics data. Importantly, four potential tumour antigen candidates—PGR, RBPJ, PARVG and MSX1—were identified and significantly correlated with better overall survival, disease‐free survival and distinct antigen‐presenting cell infiltration in EC. In addition, two different immune subtypes by consensus clustering analysis of the immune‐related genes were identified. Patients with C2 immunophenotypes exhibited superior survival outcomes and ‘hot’ immunoreactivity and harboured higher microsatellite instability scores and tumoral mutation burden but lower copy‐number variation burden. Furthermore, the distinct expression of immunogenic cell death modulators and differential microenvironmental characteristics of immune‐cell infiltration were also revealed between C1 and C2 immune‐subtype tumours. Enrichment analysis of the co‐expression of immune‐related genes showed enrichment in immune response, immune cell‐mediated immunity and antigen processing pathways. These results indicated that these identified tumour antigens can be used for developing antitumour mRNA vaccines, and tumours with C2 immunophenotypic characteristics demonstrated sensitivity and susceptibility to immunotherapy in EC.

SJI 2020 special issue: A catalogue of Ovarian Cancer targets for CAR therapy

AbstractOvarian Cancer (OC) is currently difficult to cure, mainly due to its late detection and the advanced state of the disease at the time of diagnosis. Therefore, conventional treatments such as debulking surgery and combination chemotherapy are rarely able to control progression of the tumour, and relapses are frequent. Alternative therapies are currently being evaluated, including immunotherapy and advanced T cell‐based therapy. In the present review, we will focus on a description of those Chimeric Antigen Receptors (CARs) that have been validated in the laboratory or are being tested in the clinic. Numerous target antigens have been defined due to the identification of OC biomarkers, and many are being used as CAR targets. We provide an exhaustive list of these constructs and their current status. Despite being innovative and efficient, the OC‐specific CARs face a barrier to their clinical efficacy: the tumour microenvironment (TME). Indeed, effector cells expressing CARs have been shown to be severely inhibited, rendering the CAR T cells useless once at the tumour site. Herein, we give a thorough description of the highly immunosuppressive OC TME and present recent studies and innovations that have enabled CAR T cells to counteract this negative environment and to destroy tumours.